Hamilton has built a reputation as one of the finest heritage reissue brands in the watch world. On May 20, 2026, the brand added to that reputation with the Khaki Field Mechanical 36mm “America 250.” The watch revives one of Hamilton’s rarest and most collectible military references: the FAPD 5101 Type 1 from 1970. As a result, this release is more than a simple anniversary edition. It is a faithful recreation of a genuine piece of military watch history.
For collectors interested in Hamilton’s broader catalog, our Hamilton watches collection covers the brand’s current lineup at Precision Watches.
Two Versions: The Global 36mm and the America 250 Limited Edition
One detail worth clarifying upfront: Hamilton actually released two closely related watches side by side. Understanding the difference matters before buying.
The Khaki Field Mechanical 36mm (reference H69399930) is a globally available model. As a result, it brings the 36mm design back for a wide audience. Hamilton will produce it exclusively during 2026.
The Khaki Field Mechanical 250 (reference H89399930) is the US-only limited edition. Limited to 1,776 numbered pieces, it specifically commemorates the 250th anniversary of American independence. Meanwhile, it adds commemorative packaging, an extra leather strap, and an engraved caseback.
Both watches share the same case, dial, and movement. As a result, the core wearing experience is identical. The difference comes down to availability, packaging, and the collectible angle of the numbered limited edition.
The History: The Rare FAPD 5101
Every good Hamilton reissue starts with a genuine historical reference. In this case, the inspiration is the FAPD 5101 Type 1.
The FAPD 5101 takes its name from the Field and Aviation Personnel Department. Hamilton produced the watch for US Air Force navigators during the Vietnam conflict. However, the production run was extraordinarily brief: September 1970, and that month only. As a result, surviving examples are extremely rare, and the reference has taken on grail status in the collector community.
Several details made the FAPD 5101 distinctive. The 36mm steel case was considered large for its era, when most military watches ran smaller. Meanwhile, the case featured a “Parkerized” finish, a chemical phosphate process that increased corrosion resistance while reducing reflectivity for battlefield concealment. The same process appears on combat knives and military tools.
Inside, the FAPD 5101 used the Caliber 684, a modified ETA 2391 developed specifically for aviation navigation. This movement appeared in no other watch. As a result, it remains one of the more unusual calibers in Hamilton’s military history. It featured a direct-drive sweeping seconds hand, hacking capability, a micro-regulating screw for accuracy, and an antimagnetic dust cover.
Case and Wear
Hamilton’s reissue stays remarkably close to the original. The brand is essentially in 1:1 territory here.
Key case specifications:
- Diameter: 36mm
- Thickness: 10.2mm
- Lug-to-lug: 46.2mm
- Lug width: 18mm
- Case material: Stainless steel with matte, glare-resistant finish
- Crystal: Box-style acrylic with scratch-resistant and anti-fingerprint coating
- Water resistance: 100 meters
The 36mm diameter faithfully matches the original. Meanwhile, the tool-forward design carries over almost unchanged, including the soldered fixed strap bars. The modern version does not undergo Parkerization, but Hamilton captures that spirit with an overall matte finish that resists glare.
The box-style acrylic crystal is a key part of the watch’s vintage character. However, Hamilton addressed one of the long-standing complaints about acrylic crystals: glare and reflection. As a result, the brand added a scratch-resistant coating and an anti-fingerprint treatment that meaningfully reduce those issues.
The 100m water resistance is notable. Most Khaki Field Mechanical references offer lower ratings, so this represents a genuine upgrade for everyday wear. For more on how a field watch like this should sit on the wrist, our guide on how should a watch fit covers proportions and lug-to-lug measurement in depth.
The Dial
The dial stays true to the no-nonsense legibility that defines field watches of the era. Against a matte black backdrop, every element sits in clear contrast.
The layout includes:
- Larger Arabic numerals marking the hours
- Smaller inner numerals for 24-hour military time
- A clean white minutes track
- Triangular five-minute markers with a vintage “fauxtina” tone
- An arrow-tip seconds hand with matching aged lume
- Super-LumiNova Grade X2 on hands and indexes
The most obvious difference from the vintage original is the dial branding. Military-issued watches were intentionally brandless. However, Hamilton kept the branding minimal and used a retro typeface that complements rather than detracts from the reissue’s intent. As a result, the dial reads as period-correct despite the contemporary addition.
The Movement: Hand-Wound Calibre H-50
Inside, Hamilton uses the manually-wound Calibre H-50. This movement appears throughout the Khaki Field collection and is built on the ETA C07.701 base.
Calibre H-50 specifications:
- Power reserve: 80 hours
- Frequency: 3 Hz (21,600 vph)
- Balance spring: Nivachron (enhanced antimagnetic resistance)
- Winding: Manual (hand-wound)
As a nod to the original FAPD 5101, the movement also includes a protective dust cover. As a result, the reissue references the vintage architecture not just on the outside but internally as well. Meanwhile, the hand-wound design gives the watch a more direct, tactile mechanical feel since there is no automatic rotor.
The 80-hour power reserve is a genuine modern advantage. The Nivachron balance spring also delivers improved resistance to magnetic fields compared to standard hairsprings. As a result, the H-50 combines the spirit of the vintage caliber with contemporary reliability.
How This Compares to Other Khaki Field Mechanical References
The Khaki Field Mechanical line has been available in several sizes over the years. The 36mm “America 250” returns the line to its smallest, most historically accurate proportions.
Movement: Hand-wound H-50, 80-hour power reserve
Water resistance: 100m
Production: Limited to 1,776 pieces (US edition)
Price: $725
Movement: Hand-wound H-50, 80-hour power reserve
Water resistance: 50m
Production: Standard catalog
Style: Mid-size everyday field watch
Movement: Hand-wound H-50, 80-hour power reserve
Water resistance: 50m
Production: Standard catalog
Style: Larger modern field watch
As a result, buyers who found the 38mm and 42mm versions too large now have a genuinely vintage-accurate option. Meanwhile, the upgraded 100m water resistance makes the 36mm version more versatile for daily wear than its larger siblings.
Who the Khaki Field Mechanical 36mm Is Built For
This watch makes the most sense for collectors who:
- Want a historically accurate vintage-sized field watch (36mm)
- Appreciate genuine military watch heritage rather than generic tool-watch styling
- Prefer hand-wound movements and the tactile ritual of daily winding
- Value the box-style acrylic crystal’s vintage character
- Want an accessible entry into serious Swiss mechanical watchmaking
- Collect limited editions tied to specific anniversaries or historical references
For smaller-wristed buyers especially, the 36mm proportions fill a real gap. Meanwhile, the watch also suits collectors who appreciate the broader appeal of vintage-sized watches. Our guide on why vintage watches are smaller explores why these compact proportions wear so well.
For first-time luxury watch buyers, the $725 price point makes this an accessible entry. Our guide on how much to spend on a first luxury watch breaks down what each budget tier delivers.
See Hamilton at Precision Watches
For collectors looking for an authorized Hamilton dealer near Philadelphia, Precision Watches is just outside the city in Lower Gwynedd, PA. The store is a family-owned retailer carrying the Khaki Field, Jazzmaster, Ventura, and Khaki Aviation collections.
While the America 250 limited edition has restricted availability, our showroom can introduce you to the broader Hamilton Khaki Field lineup and discuss current options. In addition, we offer in-house watch servicing and overhaul by our certified watchmakers for buyers thinking about long-term ownership.
For more industry coverage and watch release news, our watch industry news section covers the latest from major events and brand collaborations.
Final Thoughts on the Khaki Field Mechanical 36mm
The Khaki Field Mechanical 36mm “America 250” demonstrates exactly why Hamilton has earned its reputation in the heritage reissue category. The brand leaned fully into recreation faithfulness, staying true to the FAPD 5101’s design while adding genuinely useful modern upgrades.
Given the rarity of original FAPD 5101 examples, this reissue is the most realistic way for most collectors to own the spirit of that vintage piece. Meanwhile, the period-accurate 36mm sizing fills a gap that has been missing from the Khaki Field lineup. As a result, the watch should appeal both to military watch enthusiasts and to collectors who simply appreciate a well-executed vintage-sized field watch.
At $725 for the limited edition, the watch also continues Hamilton’s tradition of accessible pricing. For collectors who want genuine military heritage, hand-wound mechanics, and historically accurate proportions in one package, the Khaki Field Mechanical 36mm is one of the most compelling field watch values available in 2026.
Frequently Asked Questions About the Hamilton Khaki Field Mechanical 36mm
What is the price of the Hamilton Khaki Field Mechanical 36mm America 250?
The Hamilton Khaki Field Mechanical 36mm “America 250” limited edition is priced at $725.
Is the Khaki Field Mechanical 36mm a limited edition?
There are two versions. The America 250 edition (reference H89399930) is limited to 1,776 numbered pieces and sold in the US. Meanwhile, the standard 36mm version (reference H69399930) is not numbered but will be produced exclusively during 2026.
What movement powers the Khaki Field Mechanical 36mm?
The watch uses Hamilton’s hand-wound Calibre H-50. It features an 80-hour power reserve, a Nivachron balance spring for antimagnetic resistance, and an internal dust cover referencing the vintage FAPD 5101.
What was the FAPD 5101?
The FAPD 5101 was a navigation watch Hamilton produced for US Air Force navigators during the Vietnam conflict. It was made only during September 1970, which makes surviving examples extremely rare and highly collectible.
Why is the watch limited to 1,776 pieces?
The 1,776-piece production run references the year 1776, the year of the American Declaration of Independence. As a result, the number commemorates the 250th anniversary of American independence in 2026.
